Generally, aviaries include at least one fan to circulate air within the aviary. Often a vent is positioned at a front of the aviary to permit air to enter the aviary. A fan may be positioned at a back of the aviary to draw the air through the aviary. This form of aviary ventilation is referred to as tunnel ventilation. The air drawn through the aviary cools the aviary, assists in the drying of manure in the aviary, and removes harmful gases. Therefore, depending on the season, tunnel ventilation can be advantageous (when the weather is warm) or disadvantageous (when the air outside is cooler than is healthy for the birds in the aviary). Unfortunately, tunnel ventilation is not recommended for use during cooler months. If cold air is drawn into the aviary and directly contacts hens, the hens become stressed. Stressed hens tend to cluster together for warmth, and this can result in dangerous conditions due to overcrowding. If tunnel ventilation is not operating and the aviary is sealed to outside airflow, gases dangerous to poultry health such as ammonia can build up and create additional stress for the birds.
Traditional aviary design for efficient egg production involves the use of battery cages in which identical cages are arranged in rows and columns and connected together. Each individual cage contains several birds, and the amount of space per bird is low. Birds housed in battery cages do not have enough space to fly or move very far, so when those birds are introduced into a “cage free” environment for the first time, they must adjust their leg and wing muscles to successfully negotiate the new environment. “Cage free” indicates that the hens are able to move through a much larger space than is available in conventional battery cages.
A need remains for a ventilation system that can be used in cooler months without stressing poultry in the aviary. A need also exists for a walkway system that helps train birds familiar with the traditional battery cage environment to adjust to the cage free environment and that facilitates airflow in an aviary by efficiently circulating warm air through the aviary to reduce hot spots and cold spots while also improving manure drying in the aviary.